At an underground church service in China, you pray as quickly as you can - and hope the police do not come running in.
At the end of an alleyway in the north of Beijing, 40 Chinese Christians gather in a small classroom. At the beginning of the service, they bow their heads and pray.
Their priest, Zhang Minxuan, stands in front of them. Twenty years ago he was a barber with no interest in religion. Then he got into trouble with the Communist Party and was jailed. After that he became a Christian.
Since then he has led an underground church and been detained a dozen times.
"One day, God will bring our church out of the darkness and into the light," he tells his followers in the classroom. Their eyes shine back at him.
"I will pray for the government no matter how much they persecute me," Mr Zhang says.
"In the end I believe that God will convert them. I will never give up my relationship with God - no matter what happens."
Underground Christians make the Chinese Communist Party nervous.
There are millions of them in this country. They worship wherever they can - often in private homes.
They do not want to be controlled by Beijing, so they refuse to sign up to the state-sanctioned church.
The party is wary of any organisation that does not pledge its loyalty to the state.
At his home in Beijing, Cai Zhuohua reads from the Old Testament.
In his sitting room, next to an old television set, there is a stack of bibles.
Mr Cai is another leader in China's underground Christian movement.
He is too nervous to allow us to meet his congregation - in case the police identify them from our reports.
Cai Zhuohua has been a Christian since he was a teenager.
A few years ago he had 10,000 bibles printed and delivered to fellow underground Christians. For this, the Communist Party jailed him for three years.
"I need to spread Christianity," he says, "and I need to print the Bible and distribute it to fellow believers - but I'm stopped from doing this."
So that makes what we find in the southern city of Nanjing quite a surprise.
China has its own thriving bible makers - the Amity Printing Company.
Every day the firm prints off around 9,000 bibles. But the factory is only allowed to supply bibles to the official state-approved church - not to the underground church.
The pages coming out of the presses do not seem to have much of an effect on the workers.
"I haven't read the Bible and I don't believe in Christianity," says Zhang Guohong, who's been working at the factory for 14 years.
"I have flipped through the book, but I am here to work. There is no time for me to read it."
Amity printed its first Chinese bible in 1987. Since then the company has been getting bigger and bigger.
In February 2008, Amity will move to a new site which will be able to make a million bibles a month. That may make it the world's largest bible factory.
That is quite something for the godless, Communist state.
"Perhaps it's God's humour," says Peter Dean, Amity's production advisor, "but we are printing millions of bibles here.
"We have printed 41 million bibles for the churches in China, they are distributed out through this gate, and into the networks of churches in China."
Some of the bibles end up at the Xishiku Catholic Church in Beijing.
This church is part of China's official, state-sanctioned religious establishment.
In the Catholic church, the bishops are chosen by Beijing, not the Vatican.
Everyone here answers to the Communist Party - no one has to hide or worry about getting arrested.
On Sundays hundreds of worshippers come to celebrate early morning mass. Three services are held - there are no spare seats at any of them.
This is the kind of official Christianity that the Chinese government tolerates.
The rule is simple: if you are loyal to the Communist Party, you can pray and you can worship as much as you like.
The government wants its Christians in the state-approved church where it can see them and control them.
But Christianity is growing beyond its control. One day soon, Christians may even outnumber Communists.
In fact, the owner of the Boteli Valve Group in Wenzhou would like to see all his staff convert to Christianity.
And such a factory is not a one-off: it is part of a growing number of businesses run by Christian entrepreneurs in one of China's key enterprise zones, whose success is now being studied by the Chinese government.
As he shows me the production facilities, the factory's general manager, Weng-Jen Wau, tells me that every month, $5m (£3m) worth of industrial valves are manufactured.
About 40% of the factory's output is exported to businesses worldwide.
But he seems to have limited interest in the sales figures - he is far more concerned to tell me about the place his family's Christian faith has in the life of the factory.
Every Monday morning, the senior managers gather together and pray about the business.
"When [Christian workers] do things wrong, they feel guilty - that's the difference”--Weng-Jen Wau factory manager
And he tells me that when staff do convert to Christianity, their attitude towards their work is transformed.
"If you're a Christian you're more honest, with a better heart," he says. "The people who aren't Christians aren't responsible. I think it's very different.
"I'm not saying those people who aren't Christians are all bad, but from the percentage of the workers who are Christians, they seem to be more responsible. Also when they do things wrong, they feel guilty - that's the difference," he explains.
One of the workers I met who had recently converted to Christianity explained that he had known nothing about the religion before he started work at the factory.
But he said that his new-found faith was now a source of daily inspiration.
He told me that he was now trying to convert his friends and colleagues to Christianity.
So I asked Mr Wau how much religion was a factor when he was recruiting new staff.
"Of course I would choose the Christians first, definitely," he said. "It's very important to find the secret of social development, the so-called potential forces for a nation”--Professor Zhuo Xinping Director of the Chinese Institute of World Religions
There are obvious questions about whether the staff really have discovered Christianity, or whether they are simply responding pragmatically to a clearly defined vision for their company.
Those I met were keen to stress the significance of their new faith, and the lack of pressure to convert - though there was no disguising their bosses' clear desire to boost Christian numbers in the workforce.
But the wider role of Christian entrepreneurs in the economic success of the Wenzhou private enterprise zone has not gone unnoticed by the Chinese government.
Far from being regarded as a religious oddity, the impact of Christian-run businesses is now being studied by Chinese government officials.
At the Chinese Academy of Social Sciences in Beijing, I met Professor Zhuo Xinping, Director of the Institute of World Religions.
He specialises in the study of Christianity's growing influence in China - and has plenty to say about Wenzhou's Christian entrepreneurs.
He tells me that the city was visited by substantial numbers of Western Christian missionaries during the 19th Century and thus has - by Chinese standards - a long history of Christian faith.
Today it has an unusually high number of Christians for a Chinese city - with some estimates suggesting Christians now make up 20% of the population.
But what really interests him is the way in which the growth of Christianity and economic prosperity have happened side by side.
He tells me that Chinese researchers are considering whether in Western history there is a link between economic prosperity and Protestant Christianity - and they are questioning what that might mean for today's China.
"It's very important to find the secret of social development, the so-called potential forces for a nation," he says. "When it comes to Western countries, the majority Chinese understanding is that this potential force is Protestant Christianity."
Christian faith may sound like an unlikely component in China's future economic success.
But the notion that newfound faith can inspire a workforce to increased levels of productivity is being taken seriously not only by Christian businessmen, but by China's Communist - and officially atheist - leaders.
Christianity in China remains a dynamic and volatile confrontation of belief systems. While there are those areas like Wenzhou where Christianity is being promoted and welcomed, Beijing remains a city where unregistered underground churches get raided and parishioners get put in jail still. I wonder how many American Christians would be willing to attend secret church services under threat of arrest? So many of us complain if the service time gets moved up fifteen minutes or if the music is not familiar enough or the temperatures inside the main sanctuary are not perfectly comfortable. Millions of Chinese Christians face retribution and jail time because they go to non-State-run real church instead of attending the government-run versions. American Christians? We have it too easy. Sometimes someone expresses displeasure with our faith. Oh, rats! I might encounter hostility or someone might just look at me funny.
Frankly, a good helping of opposition tends to be good for us Christians. You lift weights, you don't pick two pounders to try to build up your biceps, you might start with fifteens or twenties and then move up to twenty-five or thirty-five or fifty pounders. I'm too old and beat up to walk the mean streets of Chicago and Gary anymore but the experiences were good for me. Can you imagine how glorious it could be to find a young man or woman in the midst of gangs and crime and poverty who was actually hungry to hear about God? Can you imagine praying with a husband and wife who had never heard the Gospel before and were anxious to become children of God? Can you imagine seeing a teenager who was so close to being a 'banger choosing to follow Christ instead?
Can you imagine walking down the sidewalk as the sun's light faded away, seeing a group of gang-bangers on the corner and acting as if you weren't even a bit scared? Can you imagine being surrounded by a bunch of bikers and realizing the only thing to do was to begin preaching from your Bible? Trust me, I would have been a fool to take a weapon to those places but I did bring a big black Bible and that kept me safer than a Kevlar vest and a semiautomatic rifle. There was always the possibility that it wouldn't, though, and that undercurrent of uncertainty and the fairly common rejection from the majority of people you spoke to was the set of weights God used to build my faith.
Can you imagine walking the streets for hours on Saturday and then spending hours on Sunday working on or driving a church bus hauling mostly kids and teenagers to and from church? Having to wake up at O-Dark-Thirty to be able to go to the bus lot and get your bus started and off to pick up the bus workers before another 15-hour Sunday of driving and church and driving - week after week, month after month? I didn't do it to be saved or to be righteous, I did it because I wanted to serve God. Now I teach teenagers and write blogs and sometimes teach adults things that will build their faith and/or help keep America from turning into another Socialist disaster.
In my next post I will tell you why I was so driven to work for God then and why I am still driven to work for Him now.